As oxidative hair bleaches or hair dyes, those of the two-pack type, each comprising a first pack with an alkalizing agent contained therein and a second pack with an oxidizing agent contained therein, are widely used. The alkalizing agent in the first pack is incorporated to obtain a light tone by heightening beaching or dyeing effect and causing oxidative decomposition of melamine granules to proceed in hair. To bleach or dye hair into a tone lighter than his or her own hair color, sufficient bleaching power is needed. When an oxidative hair bleach or hair dye is used for such purposes, alkali is required in a particularly sufficient amount because hair bleaching power generally depends upon the amount of alkali.
Conventionally, ammonia has been used as an alkali agent in general. However, ammonia has a strong irritating odor and hence, involves a drawback that it gives considerable unpleasant feeling upon bleaching or dyeing.
Attempts have, therefore, been made to use organic amines of a lower irritating odor in place of ammonia (JP-A-59106413, JP-A-01213220, JP-A-05246827, etc.). These attempts, however, cannot bleach hair into a sufficiently light shade and moreover, use of such organic amines in large amounts, due to their high remaining tendency on the scalp, leads to a problem that irritation tends to be given.